1. Field of the Invention.
The invention relates to a lighted switch or remote panel plate with multiple replaceable light emitting diodes in banks that remain lighted when one or more fail, for use in power distribution systems.
2. Description of Related Art.
The use of LED lights in power distribution control circuits are known in the art. However, they are generally on the circuit breaker itself or should an LED bulb fail, you lose indication of operating status.
Known related art includes the use of LED bulbs incorporated into a circuit breaker as depicted in U.S. Pat. No. 5,353,014 to Carroll et al., U.S. Pat. No. 5,847,913 to Turner et al., U.S. Pat. No. 3,662,369 to Vinsani et al., U.S. Pat. Nos. 4,056,816, 5,051,731 and 4,633,240 to Guim, and an LED bulb incorporated into an electrical power load center panel as depicted in U. S, Pat. No. 5,909,180 to Bailey et al.
Other known related indicator apparatus for power distribution circuits incorporate lamps for a circuit breaker such as depicted in U.S. Pat. No. 3,742,403 to Nicol and U.S. Pat. No. 3,999,176 to Kellogg et al.
None of the devices in the above references solve the problem of providing reliable and low cost indicating equipment in power handling distribution equipment. Most indicator bulbs as noted above which are incorporated into the breakers themselves, are not readily visible to operators so operators can immediately note the operating circuit status. Therefore, in power distribution equipment, pilot lights are often used for status indication. Traditionally, these have been incandescent bulbs, but these fail regularly, due to filament burn out and vibration damage. Recently, clusters of LED""s have also been used. Additionally, these traditional pilot indicators are stand alone units. This meant that the unit must be mounted and wired. The adaptation of an escutcheon plate, particularly with a control switch escutcheon plate, solves the above described problems. By incorporating LED bulbs in a switch escutcheon plate, the cost of individual lamps and sockets is saved and the cost of mounting them is also avoided.
Others have addressed these problems in different ways. For example, others have incorporated transformers and resistors into light sockets to reduce the voltage across the incandescent filament. This is very costly. Another way is to incorporate LED clusters that plug or screw into light sockets. However, when an LED bulb fails, indication is lost while they are being replaced and the use of a separately mounted lamp holder is not eliminated. Otherwise, LED bulbs have been incorporated directly into the escutcheon plate as commercially sold by Electroswitch""s light duty control switch Model No. 644-6C. However, should any of the LED bulbs fail, status indication is lost and ease of service is not present. Loss of status indication could cause an operator working on the equipment not to realize that power is present or that power is not available to operate the circuit breaker.
The results obtained by the present invention is to offer uninterrupted status indication to the user at reduced installed costs and maintenance costs. This long felt need has not been satisfied because power engineers in the power distribution equipment manufacturing industry were simply not motivated to incorporate electronics into the equipment or components to increase operating safety since the trend in the industry is to simply xe2x80x9cbuy-outxe2x80x9d commercially available off-the-shelf components.
The present invention is an escutcheon plate, with or without a switch handle for manually opening and closing a circuit, incorporating LED bulbs externally to the escutcheon plate with pairs of LED bulbs being bridges with a zener diode bridge so should an LED bulb fail, status indication will not be lost. In addition, the failed LED bulb is easily replaceable without interrupting the circuitry.
The invention is further adapted such that when a trip condition occurs, the amber or yellow colored LED bulbs flash or blink xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d repetitively, thereby giving an operator an immediate warning of a tripped circuit condition.
The present invention is a lighted escutcheon plate for power distribution equipment. It includes an escutcheon plate with terminals on a back side for electrical communication with a control power circuit. A first plurality of LED bulbs of a predetermined color is mounted in a predetermined arrangement on the escutcheon plate. The first plurality of LED bulbs is visible from the front side of the escutcheon plate, so as to provide a visual indication of an open circuit status by lighting when the power distribution circuit is opened.
A second plurality of LED bulbs of a predetermined color is also mounted in a predetermined arrangement on the escutcheon plate. The second plurality of LED bulbs is again visible from a front side of the escutcheon plate, so as to provide a visual indication of a close circuit status by lighting when the power distribution circuit is closed.
The first and second plurality of LED bulbs are electrically connected and mounted such that should any of the LED bulbs fail, the remaining LED bulbs are capable of lighting to provide the visual indication of the open or close circuit status and the failed LED bulbs are capable of being replaced from the front side of the escutcheon plate without interrupting the control power circuit.
The invention further includes a third plurality of LED bulbs of a predetermined color mounted in a predetermined arrangement on the escutcheon plate. The third plurality of LED bulbs is also visible from the front side of the escutcheon plate, so as to provide a visual indication of a trip circuit status by lighting when the power distribution circuit is tripped. The third plurality of LED bulbs is further electrically connected and mounted such that should any of the LED bulbs fail, the remaining LED bulbs are capable of lighting to maintain the visual indication of the trip circuit status. In addition, the failed LED bulbs are capable of being replaced from the front side of the escutcheon plate without interrupting the control power circuit. The third plurality of LED bulbs are also electrically connected to flash xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d repetitively when lighted due to the trip circuit status.
Generally, the first plurality of LED bulbs is arranged in one of a single row and a single column, that is, in columnar form if mounted to the respective left and right sides of the front surface of the escutcheon plate or in a row arrangement if mounted to the respective top and bottom sides of the front surface of the escutcheon plate. No matter where located, the escutcheon plate would typically be labeled by engraving or other methods known in the art, near the row or column of LED bulbs to indicate that the LED bulbs represent open circuit status.
Similarly the second plurality of LED bulbs is arranged in one of a single row and a single column as the first plurality of LED bulbs, except that the labeling on the escutcheon plate would indicate close circuit status. In addition, the third plurality of LED bulbs is similarly arranged in one of a single row and a single column, except that the labeling on the escutcheon plate would note trip circuit status. In a typical application of the invention, the third plurality of LED bulbs may be arranged in one of two separate single rows and two separate single columns, that is, there may be one row on the top side of the front surface of the escutcheon plate and a second row on the bottom side of the front surface of the escutcheon plate. This dual set of LED bulb arrangement will enhance the visibility of the flashing LED bulbs warning of a trip circuit status for the operators.
The lighted escutcheon plate, for power distribution equipment according to the invention may have two different styles or embodiments regarding the color of the first and second plurality of LED bulbs. The first plurality of LED bulbs could typically be one of green colored LED bulbs and red colored LED bulbs, and the second plurality of LED bulbs typically include the corresponding opposite color, that is, red colored LED bulbs and green colored LED bulbs.
The third plurality of LED bulbs is anticipated to be the industry standard yellowish tinted color bulbs, in particular, yellow and amber.
In order to provide reliability by having no loss of status indication despite an LED bulb failure, each of the first plurality of LED bulbs, the second plurality of LED bulbs and the third plurality of LED bulbs include a zener diode bridge circuit across each pair of LED bulbs in series succession so that should one of the LED bulbs fail, a voltage will increase across the pair of LED bulbs having the failed LED bulb to cause the remaining LED bulbs in the corresponding first, second and third plurality of LED bulbs to remain lighted, thereby not losing corresponding open, close and trip circuit status indication. For example, if there are six LED bulbs in a bank of bulbs, then each two or pair of LED bulbs is bridged with a zener diode bridge. In this case, although both bulbs would not light with the actual failure of one bulb, the remaining four LED bulbs in the bank of bulbs will remain lighted.
In most applications, it is anticipated that the escutcheon plate is a control switch plate having handle means extending from the front side of the escutcheon plate for manually opening and closing of the power distribution circuit. However, in many applications where the operator may be some distance from the control switch, a remote panel or escutcheon plate may be required to provide real time status indication to the operator. In this case, the remotely located escutcheon plate will be in electrical communication with the power distribution circuit and more than likely, directly wired into the control switch escutcheon plate terminals.